The principal commercial process for the production of pure deuterium gas is the electrolysis of heavy water (reactor grade -- 99.75% purity). In typical modern systems for the electrolysis of ordinary water the electrolyte is normally an alkaline hydroxide such as KOH. Alkaline hydroxide electrolytes are used in these units because of their good electrical characteristics and because they are particularly well suited to producing gas of high purity. When such a system is adapted for the production of pure deuterium (D.sub.2) from deuterium oxide (D.sub.2 O), an alkaline deuteroxide (KOD) rather than an alkaline hydroxide is required in order to eliminate hydrogen contamination in the generated deuterium gas. This alkaline deuteroxide electrolyte must be replenished periodically as heavy water is consumed by the electrolysis unit. However, deuterated chemical compounds are costly and can add substantially to the cost of the generated gas.